Structural and Magnetic Properties of Two Novel Fe(III) Schiff Base Complex.

FA4-MS02 Design and Properties of Functional Molecular Materials

25th _{European Crystallographic Meeting, ECM 25, İstanbul, 2009}

Acta Cryst. (2009). A65, s 240 Page s 240

FA4-MS02-P01

Synthetic,

Structural

and

Luminiscence

Properties of a New Phosphorescent Cadmium

Chloride Network with 2-aminopyrimidine. Duane

Choquesillo-Lazarte

_{, Juan Manuel García Ruiz}

_,

Antonio Rodríguez-Diéguez

_{, Enrique Colacio}

_.

_{Laboratorio de Estudios Cristalográficos,}

IACT-CSIC.

_{Departamento de Química Inorgánica,}

Universidad de Granada.

E-mail: duanec@ugr.es

In recent years the study on the self-assembly of organic and inorganic molecules in the solid state has become one of intense research activity [1] because it extends the range of new solids which can be designed to have particular physical and chemical properties. Hydro(solvo)thermal in situ metal/ ligand reactions, as a new bridge between coordination chemistry and organic synthetic chemistry [2], are of great interest for the discovery of novel coordination architectures and organic reactions.[3] Although in situ metal/ligand reactions have been extensively investigated for many decades, only a few kinds of organic ligand in situ reactions have been found under hydro(solvo)thermal conditions. The exploration of new in situ metal/ligand reactions has remained a challenge for researchers in both coordination and organic chemistry. We report the hydrothermal reaction of CdCl2 with 2-aminopyrimidine in water yielding one 2D metal-organic coordination framework [CdCl2(PymNH2)] (PymNH2 = 2-aminopyrimidine). This compound is a sheet coordination network, consisting of corner-sharing chains of Co2(μ-Cl)2 bridged by PymNH2 through ring nitrogen atoms. Additionally, this polymer exhibits strong phosphorescence at room temperature in the solid state. [1] R. Robson, B. E. Abrahams, S. R. Batten, R. W. Gable, B. F. Hoskins and J. Lieu, Supramolecular Architecture, ACS publications, Washington, DC, 1992. [2] A. Rodríguez-Diéguez and E. Colacio, Chem. Commun, 2006, 4140. [3] P. Vishweshwar, D. A. Beauchamp, M. J. Zaworotko, Cryst. Growth Des. 2006, 6, 2429.

Keywords: polymer structure; tetrazolate; luminiscence

FA4-MS02-P02

Structural and Magnetic Properties of Two Novel

Fe(III) Schiff Base Complex. Yasemin Yahsi

_{, Hulya}

Kara

_{, Orhan Buyukgungor}

_{, Anastasia Iakovenko}

_,

Lorenzo Sorace

_.

_{Balıkesir University, Faculty of}

Art and Science, Department of Physics, Balıkesir,

Turkey.

_{Ondokuz Mayıs University, Faculty of}

Art and Science, Department of Physics, Samsun,

Turkey.

_{Dipartimento di Chimica and UdR INSTM,}

Universita` di Firenze, Firenze, Italy.

E-mail: yahsi@balikesir.edu.tr

Two novel monomeric [C18H17Cl3N2O2Fe] (1) and dimeric [C38H36N4O4Cl6Fe2] (2) Fe(III) tetradentate schiff base complexes have been synthesized and their crystal structures have been determined by single crystal X-ray diffraction analysis. The compound 1 crystallizes in monoclinic space

group P2₁/c with a= 8.740, b= 15.469, c= 14.564 Å, β= 107.045° and the X-ray structure analysis of monomeric Fe(III) complex shows that the Schiff base ligand coordinates toward one iron atom in a tetradentate mode and each iron atom is five coordinated. This monomeric Fe(III) complex is such like a dimeric iron complex with the 2.89 Å non-bonding interatomic Fe…O distances and the coordination geometry around iron atom can be described as a distorted square pyramid. In compound 1 the equatorial sites are occupied by the N2O2 donor atoms

of the schiff base ligand, with average bond distances of Fe–N=2.081 and Fe–O=1.894 Å, and the apical chloride atom, with Fe–Cl=2.237 Å. The compound 2 crystallizes in triclinic space group P-1 with a=8.443, b=9.289, c= 12.600 Å, α= 82.085°, β= 79.107°, γ= 86.436° and the X-ray structure analysis of dimeric Fe(III) complex shows that the Schiff base ligand coordinates toward one iron atom in a tetradentate mode and each iron atom is six coordinated. The structure of 2 is a centrosymmetric dimer in which the iron (III) atoms are linked by µ-phenoxo bridges from one of the phenolic oxygen atoms of each Schiff base ligand to the opposite metal center and the two halves of the dimer are related by a crystallographic inversion center and the environment around each iron atom can be described as a distorted octahedral geometry. The variable-temperature (2–300 K) magnetic susceptibility (χ) data of the these two compounds have been investigated.

Keywords: magnetic properties; X-ray crystal structure analysis; iron complexes

FA4-MS02-P03

Use of [Fe(dithiooxalate)

NO]

_{as a Molecular}

Tecton in Crystal Engineering. Hulya Kara

_,

Christopher J. Adams

_{, A. Guy Orpen}

_.

_Department

of Physics, Balikesir University, Balikesir ,Turkey.

b

_{School of Chemistry, Department of Chemistry,}

Bristol University, Bristol, UK.

E-mail: hkara@balikesir.edu.tr

A series of crystalline salts based on the [Fe(dto)2NO] 2-(dto = 1,2-dithiooxalate) dianion with hydrogen bond donor cations have been synthesised following a molecular tectonics approach. The chelating Fe(dto)∙∙∙HN supramolecular synthon has been exploited in a systematic study of its robustness. The effects of competition between hydrogen-bond acceptors, of the shape and functionality of the cations are discussed. The preparation and structural characterisation of the new crystalline phases [4,4′-H₂bipy][Fe(dto)₂NO][H₂O] (1), [3,3′-H₂bipy] [Fe(dto)2NO] (2), [H2Me4bipyz]2[Fe(dto)2NO][H2O]2 (3) (Me4bipyz = 3,3’,5,5’-tetramethyl-4,4’-bipyrazole) are reported. The charge-assisted NH∙∙∙dto synthon is formed in each of compounds 1–3. Cryomagnetic susceptibility measurements on these compounds from 3.6 K to room temperature indicated the operation of an antiferromagnetic interaction between Fe(III) atoms in each case. The best fit superexchange parameters are: J₁= -12.47cm-1 _{for 1, J}

2 =-15.20 cm-1 _{for 2, J}

3= -11.34 cm-1 for 3 where H= -2JS1S2.

Keywords: iron complexes; magnetic properties; crystal engineering